In recent years, more compacted video tape recorders (VTRs) have been made available. More particularly, 8-mm VTRs are provided in a greatly reduced size with a diminished weight for use with 8-mm-wide magnetic tape.
With the development of compact and lightweight VTRs, VTRs have been introduced into use which comprise a camera unit and a VTR unit as an assembly. It is also possible to realize a portable image reproduction system which comprises a liquid-crystal television set and a VTR in the form of an assembly. Further reduced sizes are severely required for such VTRs.
Accordingly, VTRs are proposed which are variable for different modes in the depthwise length along the direction of insertion of the cassette as shown in FIGS. 41 and 42 (Examined Japanese Patent Publication SHO.61-271648).
The proposed VTR comprises a head cylinder 11 having a rotary magnetic head and mounted on a main chassis 1, a reel chassis 2 provided on the main chassis 1 and slidable toward or away from the head cylinder 11, and a supply reel support 21 and a take-up reel support 22 which are mounted on the reel chassis 2. The reel chassis 2 is driven by a chassis drive mechanism (not shown) coupled to a loading motor on the main chassis 1.
FIG. 41 shows the recorder in a standby mode, in which the reel chassis 2 is partially projected from the main chassis as indicated at A. In this state, a tape cassette 150 is loaded on the reel supports 21, 22 on the reel chassis 2.
FIG. 42 shows the recorder in a play mode, wherein the reel chassis 2 has been slidingly moved toward the head cylinder 11, which is in turn partly positioned in an opening B of the cassette 150. In this state, the magnetic tape is wound around the head cylinder 11 for recording or reproducing signals.
Thus, the depthwise length of the VTR can be reduced from L.sub.1 to L.sub.2 as illustrated. This renders the recorder convenient to carry.
The present application has invented a VTR comprising a reel chassis 2 slidably provided on a main chassis 1 as in the above VTR, and a pinch roller pressing means of a construction different from those of the prior art as will be described below (see FIGS. 5 to 7). The mechanism of this VTR is disclosed in a pending patent application filed in the Japanese Patent Office and not laid open yet.
The VTR includes a swing idler 110 which is coupled to a loading motor 31 for driving a supply reel support 21 and a take-up reel support 22. With the rotation of a loading motor 31, the idler 110 pivotally moves toward one of the reel supports and is eventually operatively connected to the reel support to transmit the rotation thereto.
In the play mode wherein a magnetic tape 151 is pressed against a capstan 12 by a pinch roller 81, as shown in FIG. 7, the tape is transported from a head cylinder 11 toward the capstan 12. The recorder is set in the stop mode wherein recording or playback is interrupted, by stopping the rotation of the head cylinder 11 and the capstan 12 in this state.
The pinch roller 81 is not released from the capstan 12 in the stop mode in order to ensure a rapid change from the stop mode to the play mode.
In the stop mode of the conventional VTR wherein the pinch roller is not released, the magnetic tape is positioned along the specified path of travel under tension and is held between the capstan and the pinch roller and thereby restrained from movement. Consequently if the conventional stop mode is used as it is for the VTR of the pending application, the following problem arises.
When the head cylinder is initiated into operation in response to a command for the change of the stop mode to the play mode, the head cylinder cannot be brought into proper operation rapidly owing to the friction between the cylinder periphery and the magnetic tape thereby resulting in faulty recording or reproduction immediately after the setting of the play mode.
This problem can be advantageously overcome by giving some slack to the magnetic tape between the head cylinder and the capstan when the play mode is to be changed to the stop mode.